(Z)-1-Phenyl-1-diethylaminocarbonyl-2-aminomethylcyclopropane hydrochloride is known as an antidepressant having and activity of serotonin-noradrenalin reuptake inhibitor.
As one of most effective methods for producing (Z)-1-phenyl-1-diethylaminocarbonyl-2-aminomethylcyclopropane hydrochloride, disclosed is a process represented by the following scheme wherein (Z)-1-phenyl-1-diethylaminocarbonyl-2-phthalimidomethylcyclopropane is treated by 40% aqueous solution of methylamine to deprotect the phthalimide group and then converted to a hydrochloride thereof by an ethanol solution of hydrogen chloride (refer to EP0200638A).

The above-mentioned process has problems that, when (Z)-1-phenyl-1-diethylaminocarbonyl-2-phthalimidomethylcyclopropane is treated by 40% aqueous solution of methylamine, by-produced N,N′-dimethylphthalamide precipitates out in a reactant mixture forming a dispersed state, thereby disturbing smooth extraction processing.
Furthermore, the process applies an ethanol solution of hydrogen chloride in the step to obtain hydrochloride salt; but since ethanol has too high solubility for (Z)-1-phenyl-1-diethylaminocarbonyl-2-aminomethylcyclopropane hydrochloride, the solubility must be controlled by adding ethers such as diethyl ether or diisopropyl ether. However, addition of ethers having high ignitability causes problems of safety in industrial applications.